It has been difficult to form rubber parts combined with a substrate at predetermined positions precisely by utilizing rubber parts molded beforehand even if grooves for fixing the rubber parts are formed on the substrate, because rubber parts extend and contract to a large extent.
In adhesive rubber parts, when the parts are adhered to a substrate, the parts are tangled with each other. In thin and long cord-like rubber parts, it is difficult to maintain a predetermined peripheral shape formed by the rubber parts because such rubber parts do not have enough rigidity.
In order to avoid such drawbacks, for example, a method for manufacturing seals for fuel cells by irradiating radioactive rays on rubber parts so as to vulcanize the rubber parts without heating, is known (for example, Japanese laid open patent No. 2002-56862).
The above-mentioned manufacturing method is explained as referring to FIG. 8.
A reference numeral “5” is a substrate used as a cathode electrode separator, a reference numeral “11” is a mask, a reference numeral “12” is openings on the mask and a reference numeral “13” is rubber layers coated on the substrate.
Rubber containing coating agent is coated on the peripheral regions of the substrate by a screen printing method so as to form rubber containing layers, which are vulcanized afterward and used in a rubber packing and the like for a seal structure of a fuel cell.
A surface of the separator 5 is covered with the mask 11, the rubber containing coating agent is applied to the separator over the mask several times so that the rubber layers 13 having a predetermined thickness are formed, the layers are vulcanized after solvent in the layers is removed and consequently, thin rubber layers adhered to the separator 5 are directly formed on the separator.
In other words, unvulcanized rubber is directly applied to the surface of the substrate so as to form the layers which are vulcanized by radioactive rays or the like without heating.
However, in order to form the layers at predetermined positions precisely, this method employ the mask through which the coating agent is applied to the separator, so that it is inevitable that the relatively thin rubber layers are obtained, because a thickness of the layers depends on a thickness of the mask.
The present invention is carried out in view of the problems mentioned above in order to provide a method for manufacturing rubber parts combined with a substrate, capable of being formed, vulcanized and adhered at a relatively low temperature and being formed in a three-dimensional shape.